Polarization-sensitive components in optical systems for large pupil acceptance angles

Patent metadata

Field	Value
Publication number	US-2022026721-A1
Application number	US-202117495751-A
Country	US
Kind code	A1
Filing date	Oct 6, 2021
Priority date	Mar 15, 2018
Publication date	Jan 27, 2022
Grant date	—

Abstract

A near eye display (NED) includes an electronic display configured to output image light. Further, the NED includes an eye tracking module and multiple optical elements that are combined to form an optical system to allow for changes in position of one or both eyes of a user of the NED. Various types of such optical elements, which may have optical states that are switchable, may be used to steer a light beam toward the user's eye. A direction of the steering may be based on eye tracking information measured by the eye tracking module.

First claim

What is claimed is:

1 . An optical system, comprising:
a first polarization-sensitive module configured to direct real-world light incident on the first polarization-sensitive module in a first direction determined based, at least in part, on eye position information; a second polarization-sensitive module configured to direct virtual-world light incident on the second module in a second direction determined based, at least in part, on the eye position information; and an optical module disposed between the first polarization-sensitive module and the second polarization-sensitive module and configured to transmit the real-world light incident on the optical module toward the second polarization-sensitive module and to direct the virtual-world light toward the second polarization-sensitive module.

2 . The optical system of claim 1 , further comprising an eye tracking module configured to determine the eye position information.

3 . The optical system of claim 1 , wherein the optical module is configured to reflect the virtual-world light toward the second polarization-sensitive module.

4 . The optical system of claim 1 , wherein the first polarization-sensitive module is configured to steer the real-world light by a first angle, and the second polarization-sensitive module is configured to steer the real-world light by a second angle that is substantially equal in magnitude and opposite in sign to the first angle.

5 . The optical system of claim 1 , further comprising a control module configured to:
transmit a first set of electronic signals to the first polarization-sensitive module to control, based on the eye position information, a first steering angle for directing the real-world light; and transmit a second set of electronic signals to the second polarization-sensitive module to control, based on the eye position information, a second steering angle for directing the virtual-world light.

6 . The optical system of claim 1 , wherein the optical module includes an optical waveguide with a light out-coupling surface that faces the second polarization-sensitive module and is configured to relay the virtual-world light along the optical waveguide to the second polarization-sensitive module.

7 . The optical system of claim 6 , wherein the optical module includes a holographic grating coupled with the optical waveguide for out-coupling the virtual-world light from the optical waveguide.

8 . The optical system of claim 1 , further comprising an image source configured to generate the virtual-world light.

9 . The optical system of claim 1 , wherein the real-world light incident on the first polarization-sensitive module has a first polarization, and the optical module is further configured to change a second polarization of the virtual-world light incident on the second polarization-sensitive module to the first polarization.

10 . The optical system of claim 1 , further comprising a lens module configured to focus the virtual-world light.

11 . The optical system of claim 10 , wherein the lens module comprises a polarization-sensitive Pancharatnam-Berry Phase (PBP) lens.

12 . The optical system of claim 1 , wherein at least one of the first polarization-sensitive module and the second polarization-sensitive module comprises a Pancharatnam-Berry Phase (PBP) grating.

13 . The optical system of claim 1 , wherein at least one of the first polarization-sensitive module and the second polarization-sensitive module comprises a switchable Bragg grating (SBG).

14 . The optical system of claim 1 , wherein at least one of the first polarization-sensitive module and the second polarization-sensitive module comprises a polarization volume grating (PVG).

15 . A near-eye display device, comprising:
an image source configured to generate virtual-world light; an eye tracking module configured to determine eye position information; a first polarization-sensitive module configured to direct real-world light incident on the first polarization-sensitive module in a first direction determined based, at least in part, on the eye position information; and a second polarization-sensitive module configured to direct the virtual-world light incident on the second module in a second direction determined based, at least in part, on the eye position information.

16 . The near-eye display device of claim 15 , wherein the first polarization-sensitive module is configured to direct the real-world light at a first angle, and the second polarization-sensitive module is configured to direct the first steered light at a second angle that is substantially equal in magnitude and opposite in sign to the first angle.

17 . The near-eye display device of claim 15 , further comprising an optical module disposed between the first polarization-sensitive module and the second polarization-sensitive module and configured to transmit the real-world light incident on the optical module toward the second polarization-sensitive module and to reflect the virtual-world light toward the second polarization-sensitive module.

18 . The near-eye display device of claim 15 , further comprising a lens module configured to focus the virtual-world light.

19 . An optical system, comprising:
an eye tracking module configured to determine eye position information; a first polarization-sensitive module configured to direct real-world light incident on the first polarization-sensitive module in a first direction determined based, at least in part, on the eye position information; and a second polarization-sensitive module configured to direct virtual-world light incident on the second module in a second direction determined based, at least in part, on the eye position information.

Assignees

• Facebook Tech Llc

Inventors

• Jamali Afsoon
• Lu Lu
• Maimone Andrew
• Moheghi Alireza
• Lam Wai Sze Tiffany
• McEldowney Scott Charles
• Lanman Douglas Robert

Classifications

• G02B27/0081

  with means for altering, e.g. enlarging, the entrance or exit pupil · CPC title

• G02B5/3016

  involving passive liquid crystal elements (optical properties of liquid crystals G02F1/0063; polarising elements associated with active liquid crystal devices G02F1/133528) · CPC title

• G02B5/32

  Holograms used as optical elements · CPC title

• G02B5/1823

  in an overlapping or superposed manner · CPC title

• G02B2027/0123

  comprising devices increasing the field of view · CPC title